Comparison of I-131 Scintigraphy , T1-201 Scintigraphy , and Serum Thyroglobulin in the Postoperative Follow-Up of Differentiated Thyroid Cancer.
- Author:
Chong Soon KIM
;
Hyun Kyung LEE
;
Jae Soon SONG
;
Joon Jae SHINN
;
Kye Hwa YOU
;
Wang Ki CHA
;
Eun Sil KIM
- Publication Type:Original Article
- Keywords:
Thyroid neoplasm;
Radionuclide imaging;
Neoplasrn recurrence;
Iodine radioisotope;
Thallium radioisotope;
Thyroglobulin
- MeSH:
Follow-Up Studies*;
Humans;
Radionuclide Imaging*;
Retrospective Studies;
Thyroglobulin*;
Thyroid Gland*;
Thyroid Neoplasms*;
Thyroidectomy
- From:Korean Journal of Nuclear Medicine
1997;31(3):346-355
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
To evaluate the utility of I-131, T1-201 scintigraphy, and serum thyroglobulin(Tg) in the follow-up of differentiated thyroid cancer, we compared retrospectively the data from 33 patients who underwent total or subtotal thyroidectomy. I-131 scintigraphy was performed after optimal endogenous TSH stimulation (TSH>50microgram/ml). Total 41 cases of I-l3l and T1-201 scintigraphy pairs were examined. Concomitant serum thyroglobulin levels were measured for 41 pairs of scan. Tg-off levels(that measured after discontinuation of the thyroid hormone) higher than 40ng/ml were considered positive, and Tg-on levels(that measured during the thyroid hormone replacement) higher than 5ng/ml were considered positive. The concordance rates between I-131 therapeutic scintigraphy and T1-201 scintigraphy was 48% in the 38 case of total scan pairs(59% in the 17 cases of postoperative preablation group, and 38% in the 21 cases of postoperative postablation group), Of 17 studies before the I-131 ablation therapy (preablation group), 7 showed positive I-131 therapeutic scintigraphy despite of negative T1-201 scintigraphy. Among patients with negative I-131 therapeutic scintigraphy, no patients had abnormal T1-201 uptake. However, of 21 studies which were done after radioiodine therapy(postablation group) 6 had abnormal uptake on T1-201 scintigraphy which were not seen on I-131 therapeutic scintigraphy, and Tg-off levels also elevated in this 4 of 6 cases. As a result, I-131 therapeutic scintigraphy showed highest positive rate at postoperative preablation follow-up study in differentiated thyroid cancer patients. T1-201 scintigraphy may be useful in postablation studies, and the use of the combined modalities(T1-201 and Tg levels) provides a higher diagnostic yield.
